On Friday, the City Rail Link (CRL) took another important step forward with the government and council officially signing agreements to create a jointly owned company to deliver the project – City Rail Link Ltd (CRLL). The new company will take over delivery of the project from Auckland Transport.

To coincide with the creation of CRLL, there is also now a new official website.

All of the press releases talk up the impact the CRL will have. Steven Joyce, who spent years opposing the project, now calls the project “game changing” while also saying that it’s important CRLL deliver a “high-quality result for the city“. Meanwhile, Transport Minister Simon Bridges says “Once complete, the CRL will fundamentally change the way people get around central Auckland” and “CRL is Auckland’s top new transport priority. It will double the capacity of the whole existing rail network and provide significant travel time savings for commuters“. The statements are interesting for two reasons.

One, it’s notable that neither Minister uses the term “transformational” when talking about the CRL, like they have done with projects like Waterview. Very few transport projects are actually transformational but if any recent transport project in Auckland was to fall into that category, it would be the CRL. To transform means to change profoundly and most of our recent motorway projects, while large, are so mply an extension of what we’ve done before. They’re all about reinforcing existing travel behaviours and land use, ultimately allowing and encouraging more driving and congestion. The CRL takes an important step towards reinventing Auckland as a metro city and one that will drive change in both how people get around and in land use.

Arguably, to find the last time Auckland saw a project as transformational as the CRL we’d have to look back almost 60 years to the Auckland Harbour Bridge. We have written about this comparison before and it’s worth keeping its story front of mind, because as I’ll explain shortly, there are likely some similar characteristics between it and the CRL. One of the key features of transformational projects is that the effects of them are usually misunderstood, even by those in favour of them or charged with delivering them. Because if a project is really transformational they will change more things than most expect.

We surely all know the story of the Harbour Bridge; that it was built too small, a condition that became apparent almost immediately, which brings us to our second point.

We’ve been increasingly wondering if the CRL is going to transformational enough, that it’s going to suffer the same fate as the Harbour Bridge and that by being underground, it won’t be as simple as to bolt on some additional capacity a few years later. In large part, what we build today will be with us for generations to come.

As highlighted from the comments above, all of the talk of the CRL is how it will double the number of trains and the capacity of the system. Doubling the capacity of the rail network is undoubtedly impressive, and we’ve sure seen some impressive growth in recent years, but it’s not exactly as if our system is starting from a really high base. We currently have around 19.5 million trips annually on the network and that is likely to grow to around 25 million by the time the CRL opens, currently expected in 2023. That suggests we could eventually see about 50 million trips per year on rail after the CRL opens.

But as we know, Auckland is expected to grow strongly in the coming decades. Between 2013 and 2043, around 700,000 extra people were expected to make Auckland home, based on Statistics NZ medium predictions. However, we’re currently exceeding even the high growth assumptions. If those trends continue we could see 1 million or more people living in the region by then. The CRL will help move a lot more people but even using the lower growth assumptions it won’t be enough.

So, we’ve been thinking about how we can get more out of the CRL. First though, here’s a few things we know about its capacity.

  • Our current trains are up to 6 cars in length and carrying up to 750 people each.
  • Our current network runs at a maximum of 20 trains per hour (TPD), 6TPH on the Western, Southern and Eastern lines and 2TPH on the Onehunga Line.
  • The CRL team have told us in the past that at opening, CRL can handle 18TPH per direction or 36 trains an hour through the tunnel
  • They’ve also said that with additional investment the capacity could be further increased to 24TPH per direction or 48 trains an hour.

That puts the ultimate potential capacity of the CRL at about 36,000 people an hour.

The first option for further increasing capacity on the network would be to reconfigure our existing trains. Currently the seats in the centre of the trailer cars have only sideways seating, as opposed to the commuter style seating in the rest of the trains. I’ve suggested before that we could replicate the seating layout of the trailer cars across the entire train. What’s lost in seats is more than made up for in standing capacity. I’m not sure exactly how many extra people that could fit on a train but as a rough guess I think it could allow an extra 80 people per 6-car train (20 extra per non-trailer carriage). That would give approximately an 11% boost to capacity (up to 40k per hour in CRL).

Next, what if we could make our trains longer. Perhaps a future fleet could have seven, eight or even nine cars per train. Assuming they also set up as described above they could give even greater capacity boosts with a 9-car train holding up to 1,250 people. By my estimations that could deliver up to 47k, 53k or a whopping 60k per hour through the CRL, about a 2/3rds increase on what is currently planned and over four times what’s currently possible. To highlight this I’ve put a little graph together showing how the capacity increases in each of the scenarios described.

Of course to run longer trains, we’d also need to make changes to our stations. This includes both the platforms and ensuring they’re designed for larger passenger volumes. In this post I’m just looking at the platforms but will look at other aspects in separate posts.

With the exception of the Onehunga line, our platforms are currently designed for 6-car trains and are a minimum of 150m long. A 6-car train is about 144m long. While I’m sure there would be some challenges, it seems that most stations outside of the CRL could have their platforms lengthened with some work. But that would leave the CRL, which we have once chance to get it right. I’ve taken a look at a few of the public CRL documents to see if longer platforms are possible, here’s what I found.


Surprisingly it appears that Aotea station is already designed big enough to handle up to 9-car trains. This long section of the station shows that there is a 150m active platform, book-ended by the escalators at each end, but that the actual platform that the public can access is much, much longer. By my estimations about 50% longer and just enough that a 9-car train could fit.

This is reinforced in this image of the future station showing the platforms extending well past the escalators on either side.

Karangahape Rd

Unfortunately, unlike Aotea there is no single long section showing the platform length, the closest I can find publicly are these two versions showing the North and South ends of the station. There’s an outline of a train on the platforms and based on that it appears that the station’s platforms will only just be long enough for the trains we have – likely a 150m platform.

I wonder what it would take to make the platforms long enough for a 9-car train.

Mt Eden

Like K Rd, it is hard to tell just how long the platforms are at the new Mt Eden station. However, it appears that based on this plan, there should be enough space. The active platform (darker grey, mostly hidden by a bridge and future development) looks to have plenty of space with which it could be extended.


Last but not least, let’s not forget about Britomart. The changes to the station to extend platforms 1 & 5 into the CRL tunnel appear to give at least enough space for an additional carriage. After the tunnels are opened the plan is also to eventually make changes to the eastern end of Britomart. The station will reduce to four platforms (to give platforms 1 & 5 more space), access from the eastern end will be improved while there will also be changes to the tracks and signalling. I wonder if part of that the CRL platforms could be lengthened enough to get to eight or nine car trains?

From looking at the various documents it appears that with the exception of Karangahape Rd. most of the stations would have enough space for at least one extra carriage, maybe more. If that is the case then it would really behove CRLL to look at ways they could make K Rd a bit longer. Especially when even a single extra carriage and reconfigured trains could add about 30% extra capacity.

Let’s not let the opportunity of the CRL go to waste and become another Harbour Bridge

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  1. Why can’t a longer train stop at existing platforms with the doors that don’t abut the platform remaining closed? Passengers at the far ends having to move a bit to access a door. Obviously it’s not ideal but it does allow more capacity at no additional cost.

    1. Capacity in the CRL will be heavily determined by the dwell, the the dwell is to high which the above example you give would cause limits capacity.

      1. Fair enough. It would be interesting to see this modelled to determine if such a solution does adversely affect dwells.

      2. The dwell needed for that little ramp coming out and going back in again might be enough already for people to walk to the next carriage.

      3. Hardly, provided the busiest stations on the network don’t require this. This scenario happens across most of the London Overground network. An announcement before arriving at the station tells unfamiliar passengers what to do, regular users figure it out pretty quickly and adjust accordingly. If the changes required to improve dwell times previously identified at this blog are implemented I doubt this would be a significant issue.

    2. I recall this (some doors not opening) is the approach for a small number of the underground stations on the DLR (Docklands Light Railway) in London, sub-optimal but can be done.

      1. Also Circle/District/Hammersmith and City undergroup lines as well as London Overground services. I would say it doubles the dwell time.

    3. That’s fine for lower volume stations further out on the network but not for the busiest stations on the busiest part of the network. All it will do is slow down dwell times, which will mean trains wont be able to follow as closely, which reduces capacity.

      1. its what they do on the wairarapa services at matarawa, renal st, maymorn &
        solway. Hard to see it work on a busy metro tho.

      2. He he. In days gone by (prior to 1991) during the morning peak they used to run a six-car set on the Johnsonville Line, even though back then all intermediate-station platforms were only 4-cars long. What’s more, all the doors opened including those on the two cars hanging off the end of the platforms. This went on for years and to my knowledge no-one ever fell out or had any problems.

        Complete contrast to the over-cautious approach of today.

        1. Clearly would have been considered over-cautious back then, when what I described was routine.

          Not saying it would be now. Just making the contrast, and suggesting that SOME of what we do today is over-cautious, leading to a level of restrictiveness not found on other modern railways.

          Flippant comment on your part, since I’m sure you knew what I was meaning.

        2. Until at least the 1980s some Sydney units had manual unlocked sliding doors, and there was nothing more pleasant on a warm summer’s day than to stand at the open doors watching the world go by, in a very pleasant breeze. Nobody worried – it was just the way things were.

        3. And still we allow manually-guided road vehicles to drive at 100Km/h (more in practice), sometimes only centimetres from opposing traffic, pedestrians and cyclists.

          We allow them to do 50Km/h through busy urban-centres and along narrow residential streets alike.

          We allow them to park at the kerbside and restrict the effective width of the road, reducing safety-margins between moving vehicles and forcing cyclists out into the danger zone.

          These vehicles mostly have manually-operated swing-out doors that can be opened at speed, or into the path of other vehicles or cyclists with potentially lethal consequences.

          We allow them to be driven by anyone who can pass some rudimentary tests, regardless of suitability in other respects.

          Railways got rid of such horribly unsafe practices years ago.

  2. A well researched thoughtful post.

    But the concept of changing the seating so a carriage can take more standing passengers took me back to my youth traveling on the London underground. You don’t realise how horrible it is until you stop doing it. Being squeezed like a sardine into a metal tin that rattles and shakes underground is like the missing chapter from Dante’s Inferno. If I, a tall male disliked being crushed against fellow passengers I can only imagine the hell for a shorter woman. Like every London commuter I’ve had my body crushed against female strangers in a way that would have had me arrested in any other location.

    To be fair this should be contrasted with the pleasant experience of sitting reading as you are moved quickly and smoothly to your office job in the city where you start work in a pleasant relaxed state.

    Why is there a limit of 36 trains per hour (18 each way)? That is putting them almost 4 minutes apart. As you may have deduced I avoid commuter travel whenever possible but my recent experience in Lille is driverless trains arriving roughly a minute apart.

    1. You’re creating a false choice – either sitting comfortably or squeezed in like sardines. The true choice is squeezed in like sardines or left behind on the platform.

    2. Its the signalling like Lille has which are the main upgrades that were referred to, to get to 48tph. Need ATO on the CRL section.

      1. Is it signalling or simple detection of the train ahead? Certainly having short driver-less light trains arriving every 90 seconds means there is not the same battle to board that is common in London and New York. The door shut – anyone stopping them shutting is soon moved either out or in and the train departs and you can see the lights on the next train down the tunnel. Lille is compact and the trains fast so nobody has to stand for long.

        1. Fail-safe detection of the train ahead (or of the absence of a train ahead) is a fundamental part of railway signalling, and is never “simple”. Lille’s network consists of individual lines, each operationally separate, while Auckland’s is part of the country’s main-line network. Apples and oranges, I’m afraid.

    3. Not saying if I agree or disagree with the binary choice given, but the situation is more complex than that. To determine the acceptability of the lesser seating plan, you have to consider the comfort of the train, the duration of the trip, the culture of the passengers.

      Duration: Currently it takes 45m from Manukau to Britomart (according to the planner) – I’ve sustained a few injuries over the years, standing for that period of time is not going to make me very happy. Result, duration makes this particular trip low viability. However, playing devils advocate, I’d only go from Ellerslie to Britomart and 20m standing (12-15 on limited stops service) is fine.

      Comfort: Our trains are air-conditioned, quiet, smooth. This increases ones endurance and what a person is willing to accept.

      Culture: Well, it can already be sardines during peak, so no real change here. However we still need to consider culture. Being a western nation, we’re quite wedded to our personal space and, being human, can only tolerate reduced peripersonal space for a limited time (an internal calculation based around value of enduring the intrusions vs the eventual outcome). A westerner is more likely to want more space around them (even in rush hour) than somebody from a nation where population density has been high for a few generations. I’ve not ridden the London underground, but I have done Hong Kong at rush hour. My partner lived in London for a few years, took the underground often. She also has spent a lot of time in HK. To her, HK rush hour was barely bearable whereas London was fine (though by no means great). I personally didn’t have any trouble with HK rush hour (careful of the acceleration!), yet I’m sometimes not very comfortable with Queen St on a Friday evening (density-wise).

      This leads on to the point that what a person is willing to bear depends upon what they perceive as normal. The perception of normality changes and I hazard that people will adapt to increased density on the trains, as that density increases over time – The only ones who’ll be caught out are the infrequent passengers, which is an issue in itself as these are opportunities lost.

      1. “Manakau to CBD” – Google replies “23 min (22.3 km) via State Highway 1” and you say the train takes 45 min. My sister lives in Farnborough and the journey to Waterloo station takes only 34 min and the distance is 64.8km.
        That sums up Auckland’s transport problems.

        1. The problem is that we don’t have 10 million people and therefore cannot support a regional and a metro network? I completely agree. Let’s really ramp up immigration to enable that.

        2. But *magically* we have enough people to support a regional motorway system including the $1.4 billion Waterview Tunnels.

          Lack of population for a better rail system in Auckland is an excuse not a reason. The current powers-that-be just prefer to build roads, that’s the truth of it.

        3. My 2nd sister lives in York and her daughter travels from Leeds 35km by train in 22min. Compares well with Manakau to CBD. Population similar to Auckland.
          Just admit NZ is crap for trains especially commuter trains. The only people who have a clue seem to be most of those contributing to this interesting blog.

        4. @Bob, sure, if we had 60m people in New Zealand then we probably could justify that level of service. For now we simply can’t and we need to make realistic calls for funding and goals (such as the CFN), we’re not going to get a separate high speed line until the upper North Island has at least 5 million people, but we sure can get a decent all day rail regional service and a metro system of the exiting heavy rail and LRT/metro right across Auckland.

          What you have described has to be a 30 year goal.

        5. That is not a fair comparison. I live in Fulham and travel to Tottenham Court Road in London. It’s a ~10km journey that takes around 40 minutes. You can’t really compare the speeds of regional trains to metro trains.

    4. With more standing room it will be less crowded, all else being equal. At worst, it would be the same level of crowdedness, I.e full, but with more people actually able to get in board.

      Keeping the status quo still means crush loaded trains, but less capacity, all else being equal.

  3. What about investment in all the other stuff – the maintenance and building of points, tracks, trains, routes, signalling systems, new building etc etc? There was a train konked out at Sunnyvale just last Wednesday that cause havoc. Underinvestment elsewhere could end up killing most of the value the CRL brings.

  4. The current Metro projects in both Sydney and Melbourne are to open with 6-car trains but with all platforms built for longer trains in the future. Because they are also wider trains than ours that means going from 1100 pax per train to 1600 later. The extra space at stations will house retail until required.

    It would be an act of hopeless shortermism to not build for this future capacity now, so difficult, disruptive, and expensive to add later, and the life of Metro systems in cities everywhere have extended way beyond the 30 year design model that we typically work to in NZ.

    Adding platform length elsewhere on the network is relatively trivial, so it’s important this option isn’t closed to future Auckland.

  5. A think any further investment in rolling stock and physical infrastructure (other then signalling) should be carefully evaluated against other corridors into the city (like light rail and BRT). There is a physical limit to what can be done and I don’t expect extending underground stations (like K’rd) will be chap, even all the other ones will require serious rework to allow for another 3 car set. Going to automatic handling of trains over the inner portion of the network and increasing frequency that way should give us better outcomes. 100 seconds headway seems to be possible in many other systems.
    Having more high capacity corridors will work better in the long term – greater resilience and coverage.

    1. Absolutely, higher frequencies will be needed, but over time it is likely that all means of increasing capacity will be useful, and, regardless of what other infrastructure is built, getting the most out of this asset (like all others) will always be valuable. We have a track record of closing off the future due to a failure of imagination and experience around cities. In Auckland we have a real one now.

      1. Equally – we should be careful not to waste efforts on ‘future’ technologies (like next generation of signalling that will allow 30 sec headway, etc). Basically – we shouldn’t wait with addressing problems until a ‘better’ solution is available. Let’s take what’s here and now. Luckily for us Auckland can easily follow the steps of other metropoleis out there when it comes to solving transport and spatial issues.

  6. ATO would get us to 24tphpd which is 2.5m headways. I think the issue with the CRL is the grades which will make getting more sets than that through a little tougher.

  7. +1. Good to see that it appears Aotea, Eden and Britomart should all be capable of 9-car EMU’s. In that case K Rd really should be also built to that standard (or be designed so that the additional length can be easily added with no impact to services or passenger amenity.

    As I have also mentioned previously there are other easy gains we can get without reducing seating as follows:
    1) New EMU’s should be ordered as permanent 6-car EMUs. The advantage of these is that they a) cost less, b) have approximately 15% extra capacity (removing 2x driver cabs plus the gap between sets).
    2) When ordering new EMU’s we can also retrofit our existing EMU fleet to be mostly permanent 6-car EMU’s. Just need to order some cab-less powered units to swap out with the current cab units. Would involve a bit of mixing and matching but we would effectively gain 15% extra capacity for no cost (bar the additional EMUs which we will be ordering anyway – and they will be cheaper since less cab-less).

    1. Yeah agree if changing the seating should be last option but I think it is good to show because shows the potential capacity.

      The issue I foresee would be however will we may need to change the seating beforehand anyway to deal with capacity problems before CRL opens.

      1. They would be stupid not to look at changing the seating earlier if it can yield meaningful capacity enhancements. It would be a comparatively cheap and quick measure to boost capacity on the network

        1. Depot was built for the current fleet, they didn’t anticipate a potentially different kind of train to use the depot.

    2. And while they’re at it, there needs to be more hand holds around the carriage entrance areas for standing passengers to steady themselves on. As opposed to other passengers…:)

      I’ve noticed the high capacity trains/metro overseas have a post in the centre of the entrance area which works well.

  8. Leave it to the professionals, or get qualified to comment! Matt, what are your qualifications? Why do you to assume to know more than the internationally experienced experts! Working at a contact centre, isn’t quite the same is it!

    1. I take it you are not one of these qualified engineers you talk about. Otherwise I imagine you would have added comment about why this could or couldn’t work.

    2. For the record, the only qualifications needed to comment on a public blog are 1) being a human being with 2) a basic sense of decency!

      Beyond that, posts and comments are evaluated based on their logic and good humour! I personally would discourage excessive use of exclamation marks! And ad hominem personal attacks!

      Incidentally, your comment violates our existing user guidelines, and makes me want to add another: “don’t be a dick”. Or should that be “!”?

    3. Your comment is worse than all these replies describe. It is condescending and self-righteous. I hope you were actually just trolling.

      The experts – including Educated Engineers – have provided us with a car-dependent city which is often only practical to access by car, and where ecology, community, public health and city layout is continually being destroyed in the name of roading projects.

      Progressive cities where motorways have been resisted or are now being removed are doing this because the people have stood up to the Educated Engineers and shown a better way.

      Matt is doing a fantastic job of bringing a wide range of topics to our notice so we can discuss them.

      From an Educated Engineer who was obviously Educated Better. In how community engagement and democratic process works, if nothing else.

    4. EE – the really good positive thing about this website is that different people come in with different backgrounds, different knowledge, indifferent opinions, and all contribute well together. I certainly comment on things I have not been trained in, and am happy to be corrected when I get it wrong. It would be great if you do have some knowledge of the subject to input that knowledge here, so that we can all benefit. Thanks.

    5. Almost all of the problems with Auckland’s transport mess are because we “left it to the experts” – internationally experienced or otherwise, it makes little difference (things are a mess in other countries as well).

      By definition, experts are very limited in their thinking – that’s why I quit engineering. the narrow-mindedness was so frustrating.

      The higher the qualifications, the narrower the focus, to the point of not being able to see the wood for the trees.

      History shows us time and again that the so-called “experts” can’t be trusted to deliver the future-proof solutions that people want and society needs.

      While it might seem that politicians are to blame, politicians believe what the “experts” tell them – that’s really the main problem: politicians capitulate to “professional advice” from “experts” that collectively have a vested interest in making things that won’t last, so they get more work later – they don’t want to produce solutions, they want an assured stream of problems.

      We need civil society to engage in building a vision, and to holding politicians and “experts” to account.

      That’s what this blog aims to do, and I think Matt and Patrick and the others involved in it do a great job and do us all a great service.

      1. I just want to support what Jamie said about the importance of civil society.

        As someone studying towards a PhD I perhaps take a softer view of experts, while supporting the need for their prognostications to be vetted by civil society.

        Life’s too complex to leave it to the experts, IMO!

        1. Exactly Jamie and Stu. Technical matters are never solely technical matters, they all have human outcomes. Also technocracies risk falling into group-think, silos, and defensiveness around their power and status (looking at you traffic engineering), which diminishes creativity and open mindedness and therefore progress.

          These kind of pitfalls are clearly in play when someone brings no argument, technical or otherwise, but simply appeals to technical superiority as a reason to shut down a point of view.

  9. I’m somewhat skeptical about the feasibility of running 9 car sets in Auckland, mainly because the costs of upgrading the network could well be quite high. I haven’t checked platform lengths etc, but I’d be worried about New Lynn, Kingsland, Avondale, Manukau, Panmure, Manurewa etc. Seems like a lot of work is involved in some places, and New Zealand’s geography is fairly complicated.

    I’m also not sure whether other aspects of the CRL stations have been designed with those flows in mind …

    Would it not perhaps be better to leave the CRL as is, and instead develop new LRT lines that are designed to poach demand from the over-cooked HR lines, especially for short trips? We could, for example, run an LRT line along Manukau Rd to Onehunga to soak up some of the demand on the southern and onehunga lines. Similarly, you could put an LRT line on New North Rd out to, say, New Lynn. East is more tricky.

    Also, even the LRT on Queen and Dominion Rd would already catch some of the existing PT demand between Mt Eden and Britomart.

    1. P.s. Edit — I should have said LRT along Manukau to Onehuna and Great South Rd to Ellerslie and then Panmure.

      1. I think the issue with Manukau road is all the bus lines that converge at Newmarket such as Eastern/Mt Wellington Buses, Rems Rd Buses, GSR, Gillies Ave Buses, Link Buses etc.

        This would make is a tad more difficult in my opinion from a network ops pov than other LRT lines like Dominion Rd which doesn’t overlap with other bus routes.

        Also you might need a second surface corridor for LRT other than Queen as if SW & NS are LRT then you need all of Queen St capacity for that.

        I am not sure if 9 car sets if feasible but 7/8 should be if K’ Road can be sorted, the biggest issue will be stations which have level crossings close to the station like Baldwin.

      2. Stu, recent newly built stations in constrained places (New Lynn, Manukau, Newmarket, Henderson) have already allowed for longer platforms, mostly 200m if I understand correctly.

        Also a lot of stations were originally much longer, and its only the modern raised platforms that are shorter. For example take a look at Remuera, Penrose, Glen Innes and others on google, you can clearly see the outline of the old island is about 200m long, of which only part has been raised to form the modern platforms.

        If the CRL is done the same, that leaves mostly just legacy platforms to be raised at above ground stations, plus the new ones on the western line. Most of those should be simple to extend, for example Avondale you just go longer, although no doubt there will be some tricky ones. Probably a case where 90% are easy and 10% end up costing a bomb.

        1. Perhaps. I don’t have much confidence in suggestions that infrastructure has been future-proofed in the NZ context. I also think the network-wide implications of such a change could be quite significant (happy to be proven wrong).

          I would have thought 9 car sets would incur substantial costs aside from adjustments to platforms at stations. E.g. track work would be needed to manage power/traction issues arising from tight curvature and relatively steep grades that exist across our network, as well as signalling costs? Or can the existing EMUs easily deal with such issues, or be updated so they have the power to manage OK?

          I’m not a rail tech expert, I’m just aware of similar proposals across the ditch that have typically not progressed due to the network wide costs involved.

          Basically, I agree we should be planning to accommodate longer train sets, but will remain somewhat skeptical until I see some detailed analysis of total costs.

          And whether 9 car sets are better than simply planing to develop alternative PT transport infrastructure to cater for short to medium distance trips is not clear to me. If we eventually think we might need LRT on Manukau and Great South Rds anyway, then perhaps it can help resolve issues with over-crowding on the HR.

        2. It’s not future proofing for the most part Stu, it’s the fact that the historic platforms were much longer than they are today. But the recent projects have been future proofed, you can go on google maps and measure Henderson, Newmarket, New Lynn. They’re all 180m min.

          Of course there will be significant impacts and costs across the network, but it’s still going to be the cheapest way to run 50% more train carriages an hour across the network.

    2. I was wondering if they should remove heavy rail from the Onehunga line and replace with double tracked light rail. Carry it on to up Elerslie Panmure highway to Pakuranga or similar. Could be a lot more frequent than heavy rail ever will be…

      1. I like this idea, it also provides a reliable, fast link between Pamure station and the southern line, which would be very useful. One issue that I can see with removing heavy rail from the Onehunga line, is that post-CRL a new place will be required to terminate Western line services.

      2. yeah I think the idea of running the OBL as LRT is worth investigating. Would reduce costs/need for grade separation.

        But you’d have to wait for a certain cantankerous AKL politician to move on before broaching that topic.

      3. Yes and aside from that, I think Auckland needs to get a lot more aggressive with planning of LRT in other main corridors (need funding of course). Cross ones like St Lukes, Balmoral, Greenlane W, Remuera Rd all the way to GI. Reduce the car lanes and add in decent cycleways etc while at it.

        1. Yes. St Lukes, Balmoral, Greenlane … what a horrible piece of infrastructure that has become. Anyone tried to take the bus to One Tree Hill with kids and discovered the lack of footpaths and crossings? Anyone seen people on the skinny footpath a couple of blocks west of St Lukes nearly get bowled over? The speed with which the traffic including buses go along there in skinny lanes makes it completely horrible for cycling and walking. LRT along there would be great. Once you put in good footpaths and street trees, do you think we should have any lanes for cars?

        2. Would have to provide sider width here and there for stations of course but a lot of the corridor seems to be wider.

        3. +1, short sections of shared path are fine, especially in areas with lower pedestrian numbers.

        4. Short sections of shared path are not fine, because they create the impression that the unshared bits in between are shared when they’re not, so cyclists continue on the footpath; they are a risk to the most vulnerable users of footpaths; and they go against the general principle that cycle provision along any particular stretch of road, which “short sections” clearly don’t conform with.

          Shared paths can be fine for new construction, but converting existing footpaths in urban areas is something to be avoided.

        5. What would you propose Mike? Not as much risk/damage as a car hitting a cyclist using the road as it stands. Pretty low ped count probaby around the side streets.

        6. I would suggest respecting the position of pedestrians, many of whom are vulnerable and have little choice but to use the footpath. If space is required within the road corridor, it should be reallocated from those who have a choice and are currently exercising a large physical and environmental footprint, not from the most efficient users of that space, who need to be there.

        7. “Short sections of shared path are not fine, because they create the impression that the unshared bits in between are shared when they’re not”

          Only if you make exactly zero effort to differentiate the shared path from the other facilities.

        8. Sadly, that’s the amount of effort that generally seems to be made – shared paths and footpaths are often barely distinguishable, so the transition from one to the other is unnoticed by users.

        9. Easily solvable then. In the short lengths where there isn’t enough space, we have the car lanes do a One Way Bridge thingy. 🙂 Or does that stuff up the LR? Solve that one for us, and we’ll let AT know we’re doing, yeah?

        10. To me surely the hardest bit challenge politically would be the car lanes so if it’s tight & parking has gone, shared paths is the best you can do if you are going to fit in LRT, the sketch up I did I think is pretty tight for both the LRT & car lanes as it is? What are the minimum general traffic lanes on an arterial road you could get away with?

        11. Yes I tend to agree. At least until the world changes a bit more. The only other possibility is making the roads one way, as they do in Copenhagen. Unfortunately that won’t work for this road, because there’s no nearby parallel road that will take the other direction.

        12. You could elevate the section over the greenlane motorway interchange so as to not muck with the roundabout too much. Have innovative artistic design so its not an eyesore with good ped access to either side one being right into the heavy rail station there. This will help ped access to the HR station too. Other access perhaps on NE corner. Cycleway could elevate with it.

        13. Get our kids to design the bridges, yeah? Good project for next term. Let them set the design specifications too. Maybe two possible paths down on each side. Gentle even slope or daredevil speedster jumps. And high barriers.

        14. You have the total width about right Grant, but the distribution wrong. I’d go 3.3 for LRT (Austroads gives minimum 6.6m for both lanes) and then go 3.3 for the general lanes too. With a kerb on both sides like you would have here, you will need a minimum of 3.2 for traffic lanes.

    3. I agree, 9 might be challenging in some places but 7 might be quite feasible. Point of the post was to question if we’re locking ourselves off from these possibilities in the future due to some assumption that what we have now is final.

      I do agree that additional routes would also help but we also know how hard they can be to get approved. I just don’t want us to get 20-30 years into the future and wish we had been a little more forward thinking

      FYI, New Lynn is one of the longest platforms on the network

    4. There isn’t room at Manurewa for another 3 cars.

      The platforms are constrained by two bridges – Weymouth Rd to the south and Southmall bridge to the north.

        1. It’s a very busy bridge and it is built on Southmall land as was the station.

          The other two entrances, and the surrounding roads, to Southmall wouldn’t be able to cope with the extra traffic.

        2. Meh who cares, are you seriously suggesting that mainting the sixth mall carpark entrance is more important than upgrading the mall train station?

          I’m sure life will go on in the southmall carpark.

        3. It’s private property.

          Good luck trying to find the absentee owners. ARTA couldn’t.

          Or are you just trolling me?

        4. The width of the rail corridor allows for the up platform to be moved back to fit the third main, the third main requires both Southmall bridges along with Station Rd and Browns Rd bridges to be replaced. The Southmall bridges will require replacement at some stage it is just a matter of how soon and who will pay.

          Also I believe in recent years Southmall changed owners and is now owned by a subsidiary of Foodstuffs NI, that is why the Woolworths/Countdown closed and New World took over the bigger site.

        5. “Good luck trying to find the absentee owners. ARTA couldn’t.”

          Compulsory purchase orders don’t require landowners to be present.

        6. Sailor Boy with just a quick look at GIS viewer on the Auckland council web site shows there is no compulsory purchase required, the rail corridor is sufficiently wide it is the bridge foundations that are on the rail corridor that are the problem. The bridges will need to be replaced when the third main gets that far it is just a matter of how soon it happens and who pays.

  10. How would you have 7 or 8 car trains? My understanding is that each EMU has 3 cars so when they’re coupled up you’re adding 3 more each time – 3, 6, and 9 ought to be the only considerations?

        1. Yes middle cars can be added (although standard rather than wheelchair capable). If needed they can also be powered which would be the main issue with the CRL gradient (they just aren’t powered now as there isn’t a need for them to be).

  11. At the risk of flogging a dead horse, an airport line via Onehunga would certainly help get better use of the CRL’s capacity. One issue with the current running pattern is that the Western line lacks a good balance, especially the trains that terminate at Newmarket. In the evening peak these trains will take a slot on the CRL but will only be heading for Newmarket so will unlikely have many passengers on them.

    There are of course many other things that count against airport HR via Onehunga but this is an important consideration.

    1. I don’t think we’re going to need to add lines to use up the capacity, I think the CRL will be more than busy enough with the current stations.

      One of the biggest benefits with the current LRT proposal is it provides a brand new route through the isthmus.

  12. Can you confirm my understanding that Aotea will be the station forecasted with the largest number of commuters using the CRL? That would mean Britomart has smaller number of patrons. Therefore the longest platforms are at the right location for long trains. They can move passengers from the ends of the train to the centre before arrival at Britomart.. right?

    1. Don’t underestimate how much growth will happen with the CRL. Just because Aotea will be mega busy doesn’t mean Britomart gets any less busy.

  13. Matt from what I can see the current EMUs could easily (and relatively cheaply) be made into 7 car units at around 168 metres long. These 7 car units would have a much larger capacity than the current 6 cars and as the passenger doors are about 5 metres in from the end these would still fit on most if not all the current platforms. Any platforms that are too short could just have an announcement that “the rear door will not open at the next platform”, giving plenty of time for anyone wanting to get off to move to a door that will.

    1. +1. Have suggested this before. Couple that with converting them to permanent 6-car (or 7 in this case) units and you would have a significant capacity increase for little cost and next to no additional running costs other than maintenance of the cars themselves.

      1. +1, the more time goes on, the more convinced I become that permanent 7 or possibly 8 car sets are the best option. Not using the far end doors is even less of a problem than people think as well as these carriages are the least full (mostly due to more seating compared to standing).

        We need a new depot anyway, so let’s build it to accommodate these trains.

      2. The CRL on it’s own will double the capacity. All of the extra works are what is needed to get up to 24 trains per hour der direction. Doing those things and extending the trains potentially quadruples the capacity.

        1. Well considering our EMUs are designed to haul themselves when fully loaded and another disabled fully loaded 6 car EMU up/out of the CRL “incline” I think they don’t need much if any powered trailer cars to make a 7 or 8 carriage EMU.

        2. The current EMUs are designed so that one set of 3 can “tow” a broken 3-car up the CRL incline – which is why they are considered to be overpowered. Adding another unpowered car would not meet that standard (although until the CRL is opened they could be used to increase capacity in the meantime since the rest of the network is much flatter). An additional car would have to be powered in some form. Although you would think that the CRL would have plenty of cross overs so that a broken down train could switch over to the down-hill line and effectively coast down to Britomart and out (to be sidelined to the Strand until it could be towed/fixed).

        3. Not necessarily so AKLDUDE, a seven car train with four standard power cars might still be sufficiently powerful to achieve that. If not the power cars could be spec’d at 15% greater output to achieve the same.

        4. The limiting factor is adhesion rather than power. In that respect the proportion of axles that are powered is the relevant metric. According to my calculations an additional unpowered car will make a CRL tunnel rescue marginal.

    2. Haven’t a lot of the “rail insiders” (James C springs to mind, but there are quite a few others ) who post/posted here spent a lot of time over the last couple of years pouring tons of scorn on the very idea of a 7+ car EMU unit for all sorts of reason (stabling, platforms, yada, yada, yada) when suggested by the likes of myself and others as a practical way to bridge the gap for capacity and staging of additional EMUs until CRL is fully operational?

      So why the sudden seeming acknowledgement by the insiders that yes, it might, you know, actually be a workable [even if only interim] idea after all?

      Eventually, we will have longer [and higher capacity] trains than the 6 car EMUs. Just like it was inevitable that the harbour bridge would have more than 4 lanes it opened with, at some point.

      You need to design for that future now, even if you don’t build all that future now.

      So why deny we need to go there at some point, so lets make sure the infra we can’t easily bolt on [like platform raising extensions to the old “legacy” platforms around the place, are forgone now by silly decisions like “we’ll never need longer trains than 6 cars” and/or “we’ll never have to cater for more than X trains an hour, each with 750 or less people on them”.

      As Patrick pointed out, we have made this exact same mistake over and over.
      Its time for a different movie to be played, one with a much happier ending.

      1. Greg N: In the long term 7+ car trains are of course workable, if you’re prepared to pay the cost in terms of platforms, depot space, signalling (yadda yadda) etc – but previous discussion was about short-term capacity fixes as an alternative to buying complete new trains.

        A long-train solution will be neither quick nor cheap, and I’m not aware of any “insider” saying anything different.

        1. Also tbh I remember the reason it got shut down was simple because it dominated threads with rehashed arguments.

      2. Greg, your comment is very vague. I personally have no idea who James C is and/or who you are referring to when you say “insiders”.

        1. Greg is correct there were several posters who wouldn’t even entertain the idea of a 7-car EMU. They would not be an issue until CRL opens and even then possibly not.

          Speaking of CRL, I see in the Herald today that Bill English said they were looking into the possibility of speeding up CRL construction to possibly 2021 in time for APEC and AmCup since Auckland is now forecast to have 100,000 more people than even the high growth forecast for next decade.

        2. Ha ha ha. It’s amazing what can be achieved when sport’s involved. English certainly needs to be seen to doing what he can, anyway. Ha ha ha. Hail to the great sports heroes.

        3. I think he is just humouring us with the CRL, I doubt it is realistic. What would be good it a decent busway and transfer station at Puhinui for airport passengers by 2021. It is probably realistic too.

        4. He specifically used the LR as an example of a project that couldn’t be done in time (yes it could be done if they really wanted to but it would involve a whole lot of things to achieve that and they are looking for lower fruit – now while the CRL is very complex, speeding up it’s construction shouldn’t be too hard – it is deliberately being built slow as a means of securing funding – so with the right funding it should be able to be built faster).

        5. English wasn’t talking about LRT to Puhinui, and he was talking about the far more complex LRT to the city centre.

          Also, I’d love to see some basis for the claim that the CRL could be sped up.

        6. Yes LR from the airport to Puhinui should be possible in time. I was referring to the LR along Dom Rd and Queen St which has been tagged as the first off the mark.

  14. Hi there what about the idea of building double decker trains like they have in Sydney and in holland??
    They are designed to fit into the same template height and width of conventional carriages

    1. The Sydney trains run in tunnels that are taller than standard (they actually have a bit of an long horseshoe shape to them).

    2. Note however that the new lines in Sydney are being built for single deck Metro style trains. One issue is that double deckers slow boarding, increasing dwell times and therefore reducing capacity of the line. Service Capacity is a result of many factors, including but not limited to, train capacity. Speed of throughput is also important.

    1. Agreed, you don’t, but you do need to design the route with these in mind from the start. For instance, the Brits can’t retrofit double decker trains as they don’t have the height (in tunnels, under bridges etc). But the Dutch planned ahead, so it has been possible since year one. However, also remember that the costs for the carriages will be substantially higher – and so all-new carriages would need to be built. They’re also double the weight, roughly, so you need to make sure you have enough horsepower to pull them.

  15. Once again we have the great and good proclaiming “CRL is Auckland’s top new transport priority. It will double the capacity of the whole existing rail network and provide significant travel time savings for commuters“
    This is confusing the necessary with the sufficient. Kiwirail chief Peter Reidy advised the transport subcommittee of Auckland Council some time ago that there was an extra billion or so which needed to be spent to get value out of the CRL. Things like sorting out the Quay Park junction/access to Ports of Auckland. I think he had about ten projects which needed completion before the CRL and a further tranche afterwards.
    About $1.5 billion all up, but ominously concluding with “and that doesn’t include any costs for eliminating level crossings.”

  16. Have modelled the CRL and broadly determined that it can handle 30 trains per hour per direction with conventional signalling. The limitation on achieving this not the CRL itself but the flat junctions elsewhere on the network.

    Grade-separating Westfield Junction alone would make a major difference to the post-CRL capacity of the system. The current Newmarket Line looks set to become less-important once the CRL opens so the benefit of grade-separating Quay Park Junction may be less clear, and Newmarket Junction would be a major job to fix. Penrose would need doing if airport rail eventually does go via Onehunga, otherwise Wiri Junction if it goes that way.

    It will be very interesting to see how things develop longer-term, but I don’t believe the CRL itself will be the overall capacity-limiter until more capacity has been freed-up on the rest of the network.

    Bear in mind, the London Underground is now designing for 36 train/hr on some of its lines (with automatic train operation). How is the CRL any different?

    1. My understanding is that the London underground lines with 36tph have no junctions, there is just a terminus at each end so the trains run back and forth. Is it really possible to have 30tph when the trains are converging from multiple different locations? If there is a delay in one it will bugger everything else up.

      There are enough delays at Quay Park at the moment.

    2. The Victoria line in London, with 36 tph, is different from Auckland in several respects:
      1. all trains are identical (no 3/6-car mixes)
      2. apart from depot journeys, all train services are identical
      3. there are no junctions, just crossovers, a depot connection and an emergency link to the rest of the network
      4. apart from the depot, the line is entirely underground, so no weather issues
      5. the line is operationally separate from any other line

      With additional rolling stock Auckland could replicate point 1, but with the CRL as part of a wider network the other points of difference will remain.

    3. Yes I think that is the sort of suggestion we got from the CRL people. If all the junctions where grade separated and the regional signalling system completely upgraded, 30tphpd could be possible.

      However, methinks longer platforms would be cheaper and easier place to start, and indeed why not allow for both?

    4. I am not saying that 36TPH would be practical as a design objective for the CRL service. But that the close headways necessary to achieve this should also be achievable on the CRL. That way, if you have a design objective of 30TPH, and the requirement to merge less-frequent contributory-services at junctions, then the additional headway capability allows a degree of flexibility for merging services to synch in with each other.

      One operating philosophy where you have multiple contributory services sharing a common arterial section, is not to stipulate a particular order of trains through the section, but to allow whatever presents itself from the contributing lines, access to the artery on a minimum-headway basis. As soon as it is known in what order trains will be arriving, “Next train will be. . . .” screens advise waiting passengers. Obviously the operator does his best to keep everything running to time, but the central artery is not then vulnerable to the inevitable late-presentation of a proportion of trains from contributing lines. One late running train needn’t “bugger everything else up”. Rather like separate tram-routes funnelled down a combined city tram-bahn.

      1. Agree regarding headways. I had assumed when the CRL is running at 24tph the minimum headway will be much closer than 2.5 mins apart though as there will always be issues with delays and the shorter the headway the quicker these issues are accounted for.

        Hopefully it is run on a first in first served basis, it would be crazy for an on time train to be waiting for a late running train to arrive so that the ‘correct’ order is maintained.

    5. Although having said that, if a contributing train runs late and misses its scheduled slot, it will likely have to displace something else when it does turn up, and this will tend to delay the whole programme. However a small amount of slippage is not usually noticed by passengers in a high-frequency system. A missed slot at 30TPH may only mean a few subsequent trains get delayed by up to 120sec, until the minimum headway capability of 100sec allows things to catch up!

      1. Agreed that close headways will be theoretically achievable on the CRL, but the absence of the distinguishing features that I mentioned above means that the risk of perturbations is much higher than on the Victoria line, so reliability would suffer.

        A passenger may not notice a slippage of 120s, but with all trains south and east having to negotiate at least three flat junctions after they’ve left the CRL I suspect that the operator would!

        1. Yes, but as stated I am assuming that at least Westfield Junction will be grade separated and possibly Quay Park also, although the lesser role of the Newmarket Branch post-CRL may make this unnecessary. Something significant needs to be done at Westfield to enable 30TPH on the CRL to work.

  17. Is it possible to run double height trains through the CRL where the lower level is recessed between the wheels (like what Sydney use)?

      1. Didn’t they trial a version of the T sets in Melbourne and they were pulled due to issues

        1. Yes, I happened to be living in Melbourne when they did that! It was a modified double-decker Taranga unit in that it was not as tall as the Sydney units so it could fit in the Melbourne network.

          Proved to be more trouble than it was worth due to the low head room in each level.

        2. It wasnt actually a Tangara at all, just looked like one as it came from the same coachbuilders. It was entirely bespoke design to try and get DDs to work in Melbourne. Did use a lot of the same off the shelf parts and fittings though.

  18. Question: Why has the Britomart redevelopment been designed to allow only the two outer tracks to flow through?

    Not sure if this has previously been covered, but seems like that could be a way to improve capacity – without presumably adding too much to existing build costs.

    Would mean new escalators, and more intensive signalling and control needed, but surely worth it for capacity gains…?

    1. @ MK: I think the answer is that since the rest of the CRL will only be twin-platformed, what is the point in allowing Britomart to have more? The only advantage is that it will enable trains to overtake each other at this particular point, should they arrive in the wrong order for any reason. However once they enter the CRL “Pipe” they just have to “go with the flow”, in the order they entered, and at the capacity set by the rest of the “pipe”. As planned, the pipe will effectively start at Quay Park Junction. Is there any advantage in having overtaking-capability at Britormart?

      Does this answer your question? Anyone else got ideas on this?

      1. Thanks for that Dave, I figured it might be that.
        I guess the other variable is that the eastern end of Britomart has two entrances/exits; Southern and Eastern lines… but yes, then still into the one loop…

        1. Not really even that, it goes back to a two track tunnel for almost a km before it splits to the southern and eastern lines… so Britomart is effectively just another station on the two track CRL.

        2. Is there a particular reason why 2 extra platforms are being keep at Britomart? As far as I can tell – trains can’t travel through the CRL to terminate there, because the tracks come from the wrong direction.

        3. Well they’re there now, why spend money to fill them in? I think also it allows some special services to terminate there that come in from the Eastern end, such as intercity trains or the Northern Explorer in the future.

        4. @Jonty
          Intercity trains was my first thought as well, however diesel trains can no longer use Britomart since the EMU’s were introduced, which is why the Northern Explorer now terminates at The Strand rather than Britomart. And if Electric Intercity Trains were introduced (wishful thinking, I know!) then I see no reason why they should not continue through the CRL as they will already have clear track to do so. And in regards to the existing platforms, it has been announced that the platfroms/tracks will be reduced from 5 to 4 to increase space for the outer CRL platforms, meaning they will need to be rebuilt anyway.

        5. Intercity trains usually stage when they terminate for next run & dwell longer

        6. Jezza, I am inclined to agree – which is why I can’t see what use there is in keeping 2 extra platforms in Britomart if there will never be capacity in the Britomart tunnel for extra trains to reach them.

          How feasible would it be to elecrify and upgrade track from Papakura to Hamilton and run the EMU’s Hamilton-Puk-Papakura-newmarket-crl?

        7. Sam – I think it it more realistic that the Britomart tunnel will be widened to three tracks at some point, including a flying junction at Quay Park. This would allow for Intercity trains to run into Britomart, probably via the Eastern line as this has the best potential for express tracks.

        8. Intercity trains need longer dwell times. Also they likely won’t be as powerful/have as much traction as our EMU’s since they won’t need to go through the CRL or need that kind of acceleration.

          Interesting to see that NZ First have released their rail policy and they intend to electrify all the way from Papakura to Hamilton and upgrade the EF loco’s.

        9. How difficult would it be to add a third track to the Britomart Approach Tunnel? Wikipedia has a figure of $150-200 million for a second tunnel with 2 more tracks. Could a third track be added without a new tunnel?

        10. The main reason is so Britomart can operate as a terminus for a large number of suburban trains in the event the CRL tunnel needs to be closed due to an incident, or for planned maintenance.

          I think there is scope for Intercity trains too however, even a very busy intercity network would be, at most, three or four trains an hour each way.

          Certainly in the early days, the CRL won’t be at capacity on day one. After that there may be some signalling/scheduling witchcraft that could squeeze a few extra slots out of the track work on the section between the Britomart platforms and QUay Park. After all, we do manage 40 trains an hour (total) through there today.

        11. Oh and widening the tunnel to a third track looks practically impossible to me. More likely would be a new tunnel under the Britomart carparking building and Quay Street to Quay Park junction. You could tie that in with grade separating the junction.

          For that the new tunnel would be the outbound track from the CRL and the northernmost platform, the existing inbound track would remain the inbound track to the CRL and the southernmost platform, while the existing outbound track could be bidirectional in and out accessing the central two platforms.

      2. The train overtaking scenario within the CRL is interesting, it always appeared the opportunity to have a third or even fourth track within the cut and cover part of the tunnel between Britomart and Aotea would be relatively simple to implement if the excavated trench was wide enough.

        1. Why? – it would add to the cost and provide little benefit as it would only be in the event of a breakdown.

        2. It would be much more cost effective to make width sufficient first dig time rather than revisit later. Benefits: storage, crossovers, breakdown provision, future proofing for more tracks,growth, other branch tunnels, etc..

        3. It will still be expensive, and all for future proofing something that may never happen, redundancy and storage. Surely no one would build an underground trench for storage!

        4. I was thinking temporary storage of train sets to allow overtaking and immediate availabilty to insert/ramp up peak services to the busiest station – Aotea
          Do we actually know that the cut and cover is built for only two tracks?

        5. According to all the plans and renders, yes. Albert St is only 24m wide, so four tracks and two platforms is basically impossible without bowling down skyscrapers.

        6. What if the space above the cut area wasn’t fully back-filled, and part of it was left as another tunnel for future use, ABOVE the CRL? Linear Park to Lower Albert St rapid bus lane? Could pop out at that weird Durham St West underground thingee. Just thinking out loud here. Hmm, might be a waste of time since Albert St will have its own bus lanes anyway. As you were.

  19. What about dive unders? Thameslink has installed one outside London Bridge Station to reduce the the number of opposing movements contesting junction points. A big increase in capacity is claimed.

    1. Mt Eden will effectively have a dive-under when finished.

      The other junctions that could benefit from this are Quay Park and Newmarket, but it is hard to see how the latter would be practicable given the tight confines and already-steep approach-gradients.

  20. Why is it necessary to have a new company, CRLL, to deliver the CRL project?
    Was AT incapable of doing this? What does CRLL bring to the process that AT could not?

  21. Maybe a bit late to the conversation here, but something that hasn’t been mentioned is the steep gradient at K Road station. It’s my understanding that the tracks go uphill from Aotea, flatten out only for K Rd station, and then continue uphill to Mt Eden station. Is it possible that the length of the flat area at K Rd is not long enough for a 9 car EMU to park?

    If I remember correctly, the climbing ability of the EMUs is what restricted the CRL designs to a set gradient incline (this is why K Rd station has to be so deep underground). Building the K Rd platform longer would either mean that either (a) the incline would need to be steeper, or (b) a longer train would need to be parking on an incline which is undesirable and probably very dangerous.

    Anyone have the technical details on this?

    1. As I understand it, the original intention was to have level stations and 1in26 gradients between. Subsequently the “need” for level stations was reconsidered and some degree of slope was accepted (not sure what) as a trade-off to reducing the between-station gradient to 1in28. The average gradient was set by the elevations at Aotea and Mt Eden, and the desirability of a consistent climb from one to the other (easing only at stations).

      Although stations on gradients are not ideal, they are not “very dangerous” and already happen all over the place. E.g. Parnell Station – 1in80, Baldwin Ave – 1in60, Kingsland – 1:45 (lessens towards the west end), and some stations on Wellington’s Johnsonville Line are at 1in40.

      The important thing with platforms is that they don’t have a transverse slope towards the tracks, with the risk that unsecured push-chairs, buggies etc can quickly roll off the edge. I believe the CRL platforms will have a transverse slope of 1in100 away from the tracks, such that anything running away longitudinally will veer towards the wall and stop there.

      1. Yes my understanding is the decision to insist on perfectly flat stations creates the main constraint on platform length. The only reason I have heard for this is the runaway pram idea. Which as you say is surely more about slope towards the track rather than along the length of the station.

        But also wouldn’t platform screen doors completely mittigate that rare occurrence? And given the lack of room for generous platforms at Aotea and the high possibility of moments of very high passenger demand there (crowded platforms), PSDs really ought to be installed there from the start?

        So with PSDs at Aotea and K Rd, and a subtle incline at these stations, as is common all over the network but unnoticed by users, real future-proofed station lengths would be able to be delivered….

        1. Thanks Dave and Patrick, well explained.

          So if the incline cannot be steeper, and it would make sense to have the platforms longer, then one way to achieve both of these things would be to build the tunnels (actually, would it just be the uphill tunnel?) between K Rd and Mt Eden “snaking” a bit to make the distance longer, giving more time to rise. Like the Raurimu Spiral, but not having to fully spiral.

          Of course, longer tunnel = higher cost…

      2. International best practise is to have a slight rise heading into a station then a slight descent heading away. The reason for this is to reduce the amount of braking needed (which generates heat) and to get the train accelerating away faster (less energy usage and slightly less heat generated).

        1. The air pressure wave from approaching tube trains on London underground was often sufficient to blow off hats and move wheeled prams, could this happen in CRL?

        2. I doubt the pressure wave will be as strong with the CRL. The CRL tunnels will be much more roomy than the tube, to allow for pantographs on the roof and emergency-egress at the side. The tube has neither of these, so the trains fit much more snugly in the tunnels and this promotes the “piston-effect”.

  22. Presumably, part of the reason there’ll be restrictions is that all lines will continue to go through Britomart? That means that not only do all trains have to be scheduled to go along one set of tracks without hitting each other, there’s also a single point of failure, meaning if anything goes wrong at Britomart, the whole network is buggered.

    It’s such an obvious bottleneck, that I’m bewildered there doesn’t seem to be any kind of plan to address it.

  23. … And is it just me, or has the rail network been having more problems recently? I’m sure there have been issues at least a few times in the last couple of weeks during rush hour on the Western line, where a number of trains would be cancelled, only to be followed by a 3 car train when it would normally be 6 cars.

    In the interest of suggesting solutions rather than just complaining, I was thinking the other day that the Western line could improve capacity (while we’re waiting for the CRL) a fair bit during morning rush hour by having trains every 5 minutes, where every 2nd train stops at Grafton and returns back out west. A lot of people seem to get off at Mt Eden and Grafton, so I think that’d get people on trains faster and ease congestion on the trains.

    1. Or have every 2nd inbound train on the WL in the mornings finish its run at Newmarket and head back out west from there. Passengers can at Newmarket cross the platform to connect to an inbound SL or OBL train.

    2. I think you’d find the 5 mins frequency unworkable for one simple reason – level crossings. With 24 trains across any given crossing within 1h that would basically mean that you get bugger all time for the cars (and pedestrians/cyclists) to cross.

      1. If they’re planning on increasing overall train frequency from 20TPH to 36TPH, with the potential to go up to 48TPH, they’re going to have to address that sooner or later, and they don’t have to wait until the CRL is complete. Besides, waiting for up to a minute every few minutes doesn’t sound that much worse than a set of lights.

        1. Given that pedestrians are slowed down at traffic lights quite a bit, it’s not a particularly good standard to have to match. If on a journey, pedestrians must stop for trains and several sets of traffic lights, it adds up to quite a delay. I would say where you know you are going to be creating delay for the trains, you’d need to compensate by reprioritising the traffic lights for pedestrians.

          Certainly the rephasing of traffic lights to smooth the flow of traffic has been shown to have no effect on car travel times within 3 years, as by then the induced traffic will have congested the intersection again. Whereas it will have had a permanent effect on pedestrian travel times, leading to less walking overall.

  24. Why on earth would you need automatic train operation to achieve 24 trains per hour? Sydney’s city railway, using bog standard traditional fixed block four aspect signalling, achieved 24 per hour when built in the 1920s. The free running headway (the theoretical minimum separation as it would be if there were no station stops) is about 75 seconds.
    The current practical maximum capacity is 20 per hour only because the double deck trains are badly designed for metro style operation and have absurdly long peak dwells at the main stations (up to 90 seconds).

  25. I think there are 3 or 4 more contracts to be let for the CRL. Possibly the contracts for the K’road and the Mt Eden stations could be settled sooner and work could begin

  26. It would be very unfortunate if the platforms in the CRL including Britomart could not accommodate 9 car trains…..

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